Related papers: Minimal Length Scale in Annihilation
Gamma ray spectral features are of interest for indirect searches of dark matter (DM). Following Barger et al, we consider 3 simple scenarios of DM that annihilates into Standard Model (SM) fermion pairs. Scenario 1 is a Majorana DM…
The spacetime short-distance structure at the Planck scale is governed by the Planck length, usually interpreted as a three-dimensional Euclidian length. As such, it is not Lorentz invariant and clashes with Einstein's special relativity,…
It is well known that a covariant Lagrangian for relativistic charged particles can lead to a vanishing Hamiltonian. Alternatively, it is shown that using a "space+time" Lagrangian leads to a new canonical momentum and minimal coupling rule…
From general supergravity theory with unified gauge symmetry, we obtain the low-energy effective Lagrangian by taking the flat limit and integrating out the superheavy fields in model-independent manner. The scalar potential possesses some…
We study renormalisable models with minimal field content that can provide a viable Dark Matter candidate through the standard freeze-out paradigm and, simultaneously, accommodate the observed anomalies in semileptonic $B$-meson decays at…
Motivated by some recent speculative attempts to model the dark energy, scalar fields with negative kinetic energy coupled to gravity without a cosmological constant are considered. It is shown that in the presence of an ordinary fluid, any…
Consider the minimal renormalizable extension of the Standard Model with purely dimensionless couplings, successful electroweak symmetry breaking (via the Coleman-Weinberg mechanism) and a see-saw mechanism for neutrino mass: we will call…
We consider a hypothetical scenario in which the Higgs boson is absent, and attempt to constrain the mass scale Lambda of the new physics that would take its place. Using recent measurements of sin^2(theta_eff^lept) and M_W, we show that,…
We analyze the dynamical implications of an exponential Lagrangian density for the gravitational field, as referred to an isotropic FRW Universe. Then, we discuss the features of the generalized deSitter phase, predicted by the new…
We propose the simplest possible renormalizable extension of the Standard Model - the addition of just one singlet scalar field - as a minimalist model for non-baryonic dark matter. Such a model is characterized by only three parameters in…
We update our earlier calculations of gamma ray and radio observational constraints on annihilations of dark matter particles lighter than 10 GeV. We predict the synchrotron spectrum as well as the morphology of the radio emission…
The general relativistic non--linear dynamics of a self--gravitating collisionless fluid with vanishing vorticity is studied in synchronous and comoving -- i.e. {\em Lagrangian} -- coordinates. Writing the equations in terms of the metric…
Detection of gamma rays from dark matter annihilation in the galactic center is one of the feasible techniques to search for dark matter. We evaluate the gamma ray flux in the case that the dark matter has an electroweak SU(2)_L charge.…
Consistency of the unconventional view of de Sitter space as a quantum theory of gravity with a finite number of degrees of freedom requires that Coleman-De Luccia tunneling rates to vacua with negative cosmological constant should be…
We study the cosmological evolution and phenomenological properties of scalar bosons in the keV to MeV range that have a tiny mixing with the Standard Model Higgs boson. The mixing determines both the abundance of light scalars produced via…
We study the dark matter from an inert doublet and a complex scalar singlet stabilized by $\mathbb{Z}_N$ symmetries. This field content is the minimal one that allows dimensionless semi-annihilation couplings for $N > 2$. We consider…
The gamma-ray line from dark matter (DM) annihilation is too weak to observe, but its observation will uncover much information, e.g., the DM mass and an nomalously large annihilation rate $\sim0.1$ pb into di-photon. In this work, we…
We study the spherically symmetric collapse of a real, minimally coupled, massive scalar field in an asymptotically Einstein-de Sitter spacetime background. By means of an eikonal approximation for the field and metric functions, we obtain…
The anomaly cancellation is a basic property of the Standard Model, crucial for its consistence. We consider a lattice chiral gauge theory of massless Wilson fermions interacting with a non-compact massive U(1) field coupled with left and…
There is considerable experimental evidence for the existence in Quantum Hall systems of an approximate emergent discrete symmetry, $\Gamma_0(2) \subset SL(2,Z)$. The evidence consists of the robustness of the tests of a suite a predictions…